This invention relates to towable seed drilling units and is particularly suitable for seed tablets and encapsulated seeds.
U.S. Pat. No. 3,880,100 (Gillies et al) which is owned by the assignee of the instant application discloses a towable seed drilling unit comprising:
A seed hopper; PA1 A seed chamber having walls and a floor formed by a portion of the lower run of an endless belt, said endless belt being regularly perforated by at least one row of holes along its length, each hole being sized to contain a single seed; PA1 Means communicating with said seed hopper and said seed chamber for providing gravity feed between said seed hopper and said seed chamber; PA1 A seed repelling roller in communication with said endless belt for agitating seed in said seed chamber; PA1 A masking plate located below said floor formed by said endless belt, the rear edge of said plate being forwardly spaced from said seed repelling roller and unmasking at least one hole in said endless belt through which a seed may fall; PA1 Means including a drive roller for carrying said endless belt; PA1 A coulter located beneath said seed chamber for forming a furrow ahead of said unmasked hole; PA1 A furrow closing member located behind said seed chamber for closing said furrow formed by said coulter; PA1 A first ground contacting wheel located in front of said coulter; PA1 A second ground contacting wheel located in back of said furrow closing member; PA1 Drive means operably associated with said second ground contacting wheel and said drive roller for driving said lower run of said endless belt in a direction opposite the direction in which said towable seed drilling unit is towed; and PA1 Means including at least one pivot arm attached to said first ground contacting wheel, a linkage system coupled to said at least one pivot arm and a manually adjustable screw operatively associated with said linkage system for adjusting the level of said towable seed drilling unit above the ground.